Robot cockroaches may be new hero in rescue missions

The compressible robot, Cram, compared with a live cockroach. The cockroach inspired scientists to create a mini-robot that can mimic its feats of speed and strength. PolyPEDAL Lab UC Berkeley / Tom LShow more

WASHINGTON // When buildings collapse, the hero helping rescue trapped people may be a robotic cockroach.

Repulsive as they may be, roaches have the remarkable ability to squeeze their bodies to one quarter their normal size, yet still scamper at lightning speed. Also, they can withstand 900 times their body weight without being injured. That’s equivalent to a 90-kilogramme human who would not be crushed by 80 tonnes on his head.

The cockroach inspired scientists to create a mini-robot that can mimic those feats of strength and agility.

The researchers hope swarms of future roach-like robots could be fitted with cameras, microphones and other sensors and then used in earthquakes and other disasters to help search for victims by squeezing through small cracks. The skittering robots could also let rescuers know if the rubble pile is stable.

Cockroaches “seem to be able to go anywhere,” says Robert Full, a biology professor at the University of California at Berkeley and co-author of a study about the prototype cockroach robot.

“I think they’re really disgusting and really revolting, but they always tell us something new.”

The study was published Monday in the journal Proceedings of the National Academy of Sciences.

The palm-size prototype, called the Compressible Robot with Articulated Mechanisms, or Cram, looks more like an armadillo and walks sort of like Charlie Chaplin when it’s compressed. It’s about 20 times the size of the roach that inspired it. And it’s simple and cheap.

Co-author Kaushik Jayaram, a Harvard robotics researcher, says the most difficult part was the design, but after that he used off-the-shelf electronics and motors, cardboard, polyester and some knowledge of origami. He could probably put one together in about half an hour, he estimates.

All told, the prototype probably cost less than US$100, Mr Jayaram says. He figures if mass-produced, with sensors and other equipment added on, the robots could eventually cost less than US$10 apiece.

In the past, when engineers looked at trying to create robots that could get into tight places, they thought about shape-changing soft animals like worms, slugs or octopuses, Prof Full says. But the cockroach, which already is studied by roboticists for other abilities, has certain advantages, including crush-resistance and speed.

With nothing in its way, the American cockroach can travel 50 times its body lengths in a second, which would be the equivalent of a human running more than 225 kilometres an hour, Prof Full said. When compressed, the cockroach slows to 20 body lengths per second.

Prof Full and colleagues found roaches used a newly identified type of locomotion to ooze through cracks and crevices based on the ideal amount of belly friction.

Cockroaches have inspired other robots, including ones that travel on six legs to get over debris more easily, said Johns Hopkins University mechanical engineering professor Noah Cowan, who was not part of the study. He says cockroaches and insects in general are great design guides for roboticists to borrow from.

“There’s definitely a case for machines that can go into environments that are not safe for humans to go into,” Mr Cowan says.

Still, the robot designers have no love for the bug that inspired them.

“I’m still creeped out by them,” Mr Jayaram says. “I don’t want them in my house. I don’t want them in my kitchen. That hasn’t changed. But we can learn a lot of interesting things from even the most disgusting animals.”

* Associated Press